Using TECs in reverse 1

[mmmmpwr]

Hello everyone

I'm not sure if this is the correct forum, but I am wondering about the feasibility of using thermoelectric cooling devices to generate a current instead of applying the power to them. We have a heat source at around 600 C and ambient air to provide the delta - would placing a TEC (like this

http://www.melcor.com/ultratec.html)

across this gradient result in a significant electrical potential? Any other ways to approach this?

Thanks for any help

 

[IRstuff]

see:

http://customthermoelectric.com/powergen.html,

among others

TTFN

FAQ731-376

 

[btrueblood]

The Melcor units the OP linked to will definitely NOT work for a 600 C hot side temperature. The materials used for the thermoelectrics (Bismuth and Tellurium alloys) will fry at temps' much above 250 C; the Melcor units also use an indium-bearing (IIRC) solder that melts at 138 C. Melcor has other units, using different solders for connections, that can operate at up to 271 (but, at that temperature the life of the chips is significantly decreased).

The units that IRstuff linked to have a listed max. Thot of 260 C, so I would bet they are also BiTe materials, though with a high-temp. solder used in their construction.

All that said, IF you have a way to ensure the heat flux thru the TEC remains fairly stable (control of the hot and cold side temperatures and/or fluid flowrates), you may be able to engineer the mounting hardware to keep the hot side below the TE chips' temperature limits. But, if (e.g.) a cooling fan fails, you fry the chip. There is a Swedish company that makes a fan to sit atop your wood stove at home, and it has been engineered as described...

http://www.wttool.com/landing/caframo_ecofan.php?utm_medium=cpc&utm_source=EcoFanLanding

There are thermopiles that can live at 600C, or even hotter, but they are made from metal alloys (e.g. thermocouple alloys), they are more expensive to fabricate and typically have lower efficiencies and output power than do BiTe TEC's.

Finally, you can also look into thermionic devices.

The above should give you a wealth of search terms you can google.

 

[Bribyk]

I've seen those fans before and thought the idea was cool. I doubt the flow created by the fan is even significant compared to the convection created by the stove itself though. If I get really bored one day I'll run the numbers...